<!doctype html>
<html>
<head>
<meta charset="utf-8">

</head>

<body>

<DIV id="CountMsg" class="HotDate">
<span id="td">00天</span>
<span id="th">00时</span>
<span id="tm">00分</span>
<span id="ts">00秒</span>
</DIV>
<script type="text/javascript">
function getRTime(){
var EndTime= new Date('2017/10/23 10:00:00'); //截止时间
var NowTime = new Date();
var t =EndTime.getTime() - NowTime.getTime();

var d=Math.floor(t/1000/60/60/24);
var h=Math.floor(t/1000/60/60%24);
var m=Math.floor(t/1000/60%60);
var s=Math.floor(t/1000%60);

document.getElementById("td").innerHTML = d + "天";
document.getElementById("th").innerHTML = h + "时";
document.getElementById("tm").innerHTML = m + "分";
document.getElementById("ts").innerHTML = s + "秒";
}
setInterval(getRTime,1000);
</script>
</body>
</html>